Is this girl trying to ruin my relationship or is she just upset ?

Hey, im 17 and im high school. This is where i met my girlfriend and we've been going out 5 moths. I really like her so i want to keep going out with her. Ive met this other girl and she is nice but just recently, she has been making me feel sorry for her and i kinda want to go out with her just to make her happy but i cant. I know she has always liked me but it got worse last week. Our maths cl had a test last week and she failed it and she started crying and i was the only other person in the cl at the time so i comforted her, gave her long hug etc as a friend though, told her everything was going to be alright etc (you need to p this test to advance in the course) after she had stop, she asked if we could talk in private, so she took me round to this corridor that was not getting used and she told me how amazing i was etc i just didn't take any notice to what was actually happening but she then opened her heart to me, she started telling me how her parents will go mad about her failing this and now she has very little friends and i was taken back quite a lot, i actually started to feel sympathy for her. She then said it was a shame i wasn't single because your an amazing person and would be the perfect boyfriend. I was Absolutely stunned. I couldn't take it in so i just said thanks and compliment her saying she's smart, Beautiful and one of my best friends. So i went home last week and i couldn't stop thinking of what she said and now i look at her and think i want to go out with her, (im evening thinking about her writing this) but i wont to stay with my current girlfriend. So i hope you get my dilemma and i hope someone can give me advice on what to do ? i want to stay with my current girlfriend but i don't want to hurt her this other girl